That reminds me of the reason I decided once and for all critical fumbles and critical hits did not need much help, [@RabidRabbit]. My Dungeon Masters loved using random tables they found which had everything from, "You just miss, as normal." to "You kill your entire party." Needless to say, you can imagine when we rolled back to back fumbles of "You kill your entire party." we threw those rules out the window once and for all. There are only a few times critical tables, good or bad, come to make sense in my experience, and most tend to be significantly more punishing to attack roll based classes than they should be. Magic is already good enough, rather exceptional, no reason to make bad worse!